Shut-off device for a fluid

Abstract

A shut-off device for a fluid includes a housing conducting the fluid, an inflow opening provided in the housing, an outflow opening provided in the housing, a flow channel formed in the housing between the inflow opening and the outflow opening, and a blocking device arranged in the flow channel. The blocking device has a blocking body receptacle and a blocking body movable in the blocking body receptacle. The flow cross-section for the fluid in the blocking device, and thus in the flow channel, can be changed by moving the blocking body in the blocking body receptacle. A reliable detection of the position of the blocking body is ensured in that an ultrasonic measuring device is arranged in or aligned on the housing such that the position of the blocking body can be determined by means of the ultrasonic measuring device.

The invention claimed is: 
     
       1. A shut-off device for a fluid, comprising:
 a housing conducting the fluid; 
 an inflow opening for the fluid, which opening is provided in the housing; 
 an outflow opening for the fluid, which opening is provided in the housing; 
 a flow channel formed in the housing for the fluid between the inflow opening and the outflow opening; and 
 a blocking device arranged in the flow channel, wherein the blocking device has a blocking body receptacle and a blocking body movable in the blocking body receptacle; 
 wherein a flow cross-section for the fluid in the blocking device, and thus in the flow channel, is changeable by moving the blocking body in the blocking body receptacle; 
 wherein an ultrasonic measuring device is arranged in or aligned on the housing such that a position of the blocking body is determinable using the ultrasonic measuring device; 
 wherein the shut-off device further comprises a control and/or evaluation unit, wherein the control and/or evaluation unit controls the ultrasonic measuring device to emit a transmitted signal, the transmitted signal is reflected at the blocking body and the control and/or evaluation unit detects the reflected signal and determines the position of the blocking body and/or a change in the position of the blocking body by evaluating at least the reflected signal; 
 wherein the control and/or evaluation unit determines an acoustic velocity in the fluid itself using a measurement with ultrasonic signals in the fluid conducted in the housing to determine the position of the blocking body; and 
 wherein a calibration measuring path is formed in the flow channel for determining the acoustic velocity in the fluid conducted in the housing, with at least one calibration ultrasonic transmitter, at least one calibration ultrasonic receiver and at least one calibration reflector, wherein the calibration measuring path is independent of the position of the blocking body and the calibration measuring path is traversed by a measuring signal in both possible traversing directions. 
 
     
     
       2. The shut-off device according to  claim 1 , wherein the ultrasonic measuring device has an ultrasonic transducer designed as a transmitter and receiver, or the ultrasonic measuring device has an ultrasonic transducer designed as a transmitter and a separate ultrasonic transducer designed as a receiver. 
     
     
       3. The shut-off device according to  claim 1 , wherein the position of the blocking body is determined by the control and/or evaluation unit by one of evaluating an intensity of the reflected signal, by measuring a transit time, by determining a phase difference between the transmitted signal and the reflected signal or by determining a frequency difference between the transmitted signal and the reflected signal. 
     
     
       4. The shut-off device according to  claim 1 , wherein the control and/or evaluation unit controls the ultrasonic measuring device for emitting a transmitted signal for cleaning the blocking body of the blocking device. 
     
     
       5. The shut-off device according to  claim 1 , wherein the position of the blocking body determined by the control and/or evaluation unit is compared to a reference position of the blocking body by the control and/or evaluation unit; and
 wherein the reference position of the blocking body is a desired position of the blocking body or a position of the blocking body determined by other means. 
 
     
     
       6. The shut-off device according to  claim 1 , wherein the blocking device is designed as a valve with an axially movable closure part with a sealing surface as blocking body and with a seal seat formed in the blocking body receptacle for sealing with the sealing surface of the blocking body in a closed state, or the blocking device is designed as a gate valve, shut-off valve or as a ball valve. 
     
     
       7. The shut-off device according to  claim 1 , wherein an ultrasonic transducer of the ultrasonic measuring device designed as a transmitter forms the calibration ultrasonic transmitter, an ultrasonic transducer of the ultrasonic measuring device designed as a receiver forms the calibration ultrasonic receiver, and the calibration reflector is arranged adjacent to the blocking device so that the calibration reflector reflects at least part of a transmitted signal emitted by the calibration ultrasonic transmitter to the calibration ultrasonic receiver. 
     
     
       8. The shut-off device according to  claim 1 , wherein the calibration ultrasonic transmitter and the calibration ultrasonic receiver are each formed by an ultrasonic transducer designed as a transmitter and receiver, wherein the calibration ultrasonic transmitter and the calibration ultrasonic receiver are different from ultrasonic transducers of the ultrasonic measuring device. 
     
     
       9. The shut-off device according to  claim 8 , wherein the calibration ultrasonic transmitter, the calibration ultrasonic receiver and the calibration reflector form a V-shaped calibration measuring path in an inlet region between the inflow opening and the shut-off device, or in an outlet region between the shut-off device and the outflow opening of the flow channel. 
     
     
       10. The shut-off device according to  claim 1 , wherein the control and/or evaluation unit carries out a transit time measurement via the calibration measuring path and determines a flow velocity using the transit time measurement.